双孔切槽爆破裂纹扩展的动焦散实验  

Ddynamic caustic experimental study of crack propagation in two borehole cut blasting

作　　者：杨仁树[1,2] 王雁冰[1,2] 杨立云[1] 许鹏[1] 

机构地区：[1]中国矿业大学(北京)力学与建筑工程学院,北京100083 [2]深部岩土力学与地下工程国家重点实验室,北京100083

出　　处：《中国矿业大学学报》2012年第6期868-872,共5页Journal of China University of Mining & Technology

基　　金：国家自然科学基金重点项目(51134025);中央高校基本科研业务费专项资金项目(2011QL06)

摘　　要：应用爆炸加载动态焦散线测试系统,研究了不同切槽方式下,双孔同时起爆时贯穿裂纹的扩展行为及裂纹尖端应力强度因子的变化情况.实验结果表明:炮孔间两切槽方向优先扩展的主裂纹,裂纹尖端并未直接相遇,而是发生偏转并移向异方已经形成的裂纹.裂纹扩展速度先减小,振荡变化后逐渐升高到峰值,随后减小,振荡变化后直至裂纹止裂.应力强度因子KI由初始时的最大值迅速减小,反复振荡后,又逐渐增大至第2个峰值,之后开始减小.定性的分析了应力波与裂纹尖端相互作用机理.A blast loading system using dynamic reflected caustics was used to study V-notch, two borehole blasting with simultaneous initiation. The crack propagation and changes in stress intensity at the crack tips was observed. The crack tips do not meet directly but are deflected and become anisotropic. The crack propagation velocity first decreases, oscillates, and then gradually increases to a peak followed by a decrease until the oscillations stop. The stress in- tensity factor, K1, is maximum at the initial point but then decreases, oscillates, and gradually increases to a second peak. The interaction mechanism between stress wave and crack tip is analyzed qualitatively.

关 键 词：双孔爆破 裂纹扩展 动态焦散线 应力强度因子 

分 类 号：O346.1[理学—固体力学]